1. Field of the Invention
This invention relates to processes for preparing yeast food products. More particularly, it relates to an alkaline extraction process for preparing yeast whippable proteins and/or acid-soluble proteins.
2. Description of the Prior Art
Protein ingredients such as egg white, casein, sodium caseinate, and dried milk solids, are useful in food applications primarily because of their functional properties such as whippability, emulsification capacity, gelability, solubility, etc. Unfortunately, they are expensive and in short supply. Yeast materials, especially those processed products having a bland flavor and reduced purine content, have the potential to replace some of these protein ingredients in various food applications. It is necessary, however, to efficiently extract the proteins from the yeast cell and process them properly to obtain the desired functional properties.
One method of removing the proteins from the yeast cells is by alkaline extraction. An example of this process is provided in U.S. Pat. No. 3,862,112. The efficiency of such a process is determined generally by the combined effect of alkalinity, reaction temperature, reaction time, and to a certain extent the cellular material concentration. Both the yield and the functional properties of the recovered protein are closely related, and after digestion in the hot alkali solution, the processed yeast material contains a complex mixture of various cellular components and hydrolysis products in both soluble and insoluble forms. These various materials greatly affect the quality of the protein product in terms of composition and functional properties.
Accordingly, it is an object of this invention to develop a process for preparing functional yeast proteins.
It is a further object of this invention to produce a yeast whippable protein.
These and other objects will become apparent upon further reading of this specification.